This invention relates to electrical smoking articles, and more particularly to electrical smoking articles having a continuous web containing a tobacco flavor medium, as well as to a replaceable cassette enclosing the continuous web.
One type of electrical smoking article is disclosed in commonly-assigned U.S. Pat. Nos. 5,060,671 and 5,095,921, which are hereby incorporated by reference in their entirety. In such an electrical smoking article, a flavor portion of a tobacco flavor medium, such as tobacco or tobacco-derived substances, is heated electrically to release a tobacco flavor substance. As the substance is heated, a smoker at the mouth or downstream end of the device draws air in and around the heating element by inhaling, and thereby receives the tobacco flavor substance.
The above-identified patents disclose a number of possible heater configurations, many of which are made from a carbon composite material formed into a desired shape. For example, one configuration involves a radial array of blades connected in common at the center and separately connectable at their outer edges to a source of electrical power. By depositing tobacco flavor medium on each blade and heating the blades individually, one could provide a predetermined number of discrete portions of tobacco flavor substance to the smoker. Other configurations included various linear and tubular shapes, subdivided to provide a number of discrete heating areas. Alternatively, semiconductor heaters, such as those described in copending, commonly-assigned United States patent application Ser. No. 07/943,505, filed Sep. 11, 1992 and hereby incorporated by reference in its entirety, can be used. Additional heater configurations are also disclosed in application Ser. No. 07/943,505, as well as in copending, commonly-assigned United States patent application Ser. No. 07/943,504, filed Sep. 11, 1992 and hereby incorporated by reference in its entirety.
Other configurations have been proposed. For example, various arrays of discrete fingers or blades of heater material can be provided, each blade providing one puff. However, suitable heater materials, such as those described in said above-incorporated U.S. Pat. No. 5,060,671, are generally not strong enough to be arranged in such a blade configuration without threat of blade breakage.
As disclosed in said above-incorporated U.S. Pat. No. 5,060,671, such heating elements are preferably disposable and replaceable. Therefore, they should be relatively inexpensive to produce. Further, there should be a way of easily applying tobacco flavor medium to the heating elements so that each activation of a heating element delivers one portion or "puff" of tobacco flavor substance to the smoker, while preventing reheating of any one portion of tobacco flavor medium.
In addition, the replaceable heater/flavor units heretofore described contain a limited number of individual charges of tobacco flavor medium, and thus provide a limited number of portions or puffs of tobacco flavor substance to the smoker. For example, a heater/flavor of the type described above might provide eight or ten puffs, to mimic a conventional cigarette. That requires the smoker to continually change heater/flavor units throughout a day of using the electrical smoking article. Each time the heater/flavor unit is changed, additional wearing of the contacts on the permanent portion of the article occurs. Also, each spent heater/flavor unit increases the volume of material disposed of.
It would be desirable to be able to provide an electrical smoking article in which the tobacco flavor medium is contained in a substantially continuous tobacco flavor web.
It would also be desirable to be able to provide a replaceable flavor or heater/flavor unit for such an electrical smoking article which can provide a relatively large number of flavor portions, to reduce the wear on the permanent portion of the article, to reduce the volume of material disposed of, and to increase the convenience for the smoker.
It would further be desirable to be able to provide a replaceable flavor or heater/flavor unit for such an electrical smoking article which can be manufactured easily and at relatively low cost.